kevin campbell, a cardiologist. kevin, dr. campbell, we thank you for joining us today. it is good to see you. this is a very important topic because there is a lot of snow out there. so there is lot of shoveling going on. people go out there without warming up. take us through the pacing what a person should do before they go out to try to shovel snow from infront their homes. >> so the cold weather puts a lot of undue stress on the cardiovascular system. we know that when temperatures drop and we exert ourselves quickly outside, that our blood pressure raises quickly and that we also put undue stress on the heart muscle itself. really in people who are predisposed to having heart attacks this could really set them off and cause a cardiovascular event to occur. kelly: you know, sometimes even trudging through the snow, if you're out there playing with loved ones, it is a wonderful day. we can't go anywhere. let's go outside to make a snowman and play a snowball fight. even that could lead to a crisis of the heart because of cold temperatures but movement, the exertion.